Thread: Confusing - distributors for 3.9L V8

OK - update.

New plugs in all pots - they were all sooty, but I expect that's because it has been running awfully when it ran at all. It still won't idle without more than 12 degrees advance measured off #1 on pulley with timing light and is extremely hard to start. Even then, on both LPG and ULP it stumbles badly if the throttle is opened too fast.

The dwell is all over the shop with the light.

At least I can now pull the thing out and establish what it what.

Getting the distributor apart is pretty simple. Watch out for the plastic retainer which will have gone hard and does not come on its own as a repair part. There are ways to fix involving drill and tap through the top of the spindle into the shaft and there is a parts kit for the whole distributor whose part number escapes me, but I'll post it if I find it.

Shaft drive gear may be a problem, camshaft gear might be a problem. Sounds like it's too retarded if it's hard to start and won't rev. Like you I hold out for the distributor guts!

Keep us in the loop.

Good luck

Pete

More progress.

The dizzy is out and disassembled. Mechanically it appears to be fine.

Even though this is proving NOT to be a binary type electrical problem (all on or all off, permanently) I am going to replace the amplifier and leads. This morning first I had NO spark at all, then suddenly I had reasonable spark, but it stumbled on LPG when booted off idle (worse with a load in gear) but much less so on ULP. Issue is back to spark strength even when spark is present.

I am so tempted to bin the whole Lucas bizzo and go for a Scorcher. They seem to be well regarded here and overseas - even in the UK - and I need to speak to the Nunawading ignition people about a set of Magnecor leads anyhow.

Look, there is nothing wrong with the Lucas distributors, as long as the bushes do not have any play.
A scorcher probably gives a better feel because it has a more aggressive advance curve as the Lucas is very conservative. A dizzy place can regraph a Lucas for much less than $600 . Tell them to graph it same as a scorcher and it will feel the same.LOL
I suggest you spend money elsewhere if you want the car to run right. There are hundreds of thousands of cars running perfectly with Lucas dizzys as long as they have good rotors, good caps, good plugs, good leads, good electronics and good bushes.
Regards Philip A

I have solved it.

It's the 5 year coil I bought from a certain spares place in Middleborough Rd, Blackburn.

Mechanically the distributor was fine, and just as a last gasp before doing something expensive, I thought I would try the original Bosch coil that was in the Disco when I bought it. The Bosch was swapped out chasing an ignition problem which turned out to be a non-genuine rotor button. It sat in the drawer ever since because the other one worked fine.

Upon swapping the no-name Shizenhousen part with the old Bosch the motor roared back into life almost as soon as the key was turned. What is even more curious is that I could return the timing back to where it was originally (about 6° advance at idle) and it ran. Swapping to the Shizenhousen coil it wouldn't start without at least 12° advance. and would die if retarded to 6°. I swapped back and forth another time and just drove it about 60km. No problem.

I know it's 5 years old, in my experience coils either work perfectly or fail utterly. This one will generate good spark when earthed to the block, but no good when feeding the distributor. No more parts from them...

Good result. Ask for a refund. LOL.

Pete

Ah, the Blackburn mob strike again.

Went and spoke to the helpful bods at Performance Ignition in Nunawading today and bought a new set of 7mm spiral wound leads - supposedly their lowest resistance leads. Yet to install them, but even just the old coil and new plugs has made a huge difference. I'll be heading back to get a change over vac advance unit from them.

Annoyingly, I just missed out on a used distributor with a very low buy it now on ebay last night. Too busy working!